CAY10680 is a dopamine-sparing, benzothiazinone compound that selectively inhibits both MAO-B activity (IC50 = 34.9 nM in human) and adenosine A2A receptors (Ki = 39.5 nM in human). It demonstrates significantly less potent inhibitory values for other adenosine receptor subtypes (Kis > 1 μM) and MAO-A (IC50 ≥ 10 μM). At 1-20 μM, CAY10680 has been shown to abolish cAMP accumulation in CHO cells transfected with adenosine A2A receptors. In the central nervous system adenosine A2A receptor expression is localized to dopamine-innervated areas where heteromeric complexes are formed with dopamine D2 receptors. Because inhibition of adenosine A2A receptors has been shown to enhance D2 receptor function, the blockade of adenosine A2A receptors has emerged as a potential treatment for Parkinson's disease. An additional strategy in the treatment of Parkinson's disease has been to block the activity of monoamine oxidase B (MAO-B), the enzyme involved in dopamine catabolism.